Objective: To increase understanding of the neural mechanisms subserving control of anal continence and coordination of defecation at spinal and supraspinal levels. The Problem: Anal incontinence is a frequent complication of obstetric and surgical procedures in perineal regions and rectal prolapse. Equally important, preservation of life of patients with debilitating systemic diseases and neuromuscular disorders add further numbers to the group of patients with deranged sphincters. Goal: The extended goal of this investigation is the design of rational therapeutic approaches, either by reconstructive surgery, autogenous transplantation of striated muscles, or by electrical stimulation to selected and specified muscles, to re-establish anal continence. Fundamental neurophysiological knowledge on control of this neuromuscular system, knowledge necessary to achieve this goal, is not available. Research Plan: The studies proposed in this application will therefore attempt: (1) to establish the segmental spinal organization and characteristics of reflex behavior of individual components of the levator ani, caudoanalis, caudorectalis and of the external ani sphincter muscles; (2) to characterize the response profile, time and amplitude of integrated EMG discharges of individual muscles of the pelvic floor to cutaneous, proprioceptive and visceral stimuli, and, (3) to identify and analyze the organization of subcortical and cortical projection regions receiving afferences from caudopelvic muscles and their projecting paths. Tonic vibratory stimuli will be used to selectively activate muscle spindles. The tonic component of the stretch reflex will be evaluated peripherally by recording the force and EMG from the activated muscle. Experiments of section 1 will be carried out in spinal cats (sectioned between C1 and C2 levels) to evaluate the behavior of this muscular system in paraplegia, and in anesthetized cats with intact neuraxis. Experiments of sections 2 and 3 will be done in intact anesthetized (chloralose 60 mg/kg) cats.